Effect of mineral diets on the development of cartilage material properties

Vitamin D and minerals, including zinc (Zn) and manganese (Mn), are vital in the development of bones, but their roles in the development of articular cartilage material behavior are not well understood. In this study, articular cartilage material properties from a hypovitaminosis D porcine model were evaluated. Pigs were produced by sows fed vitamin D deficient diets during gestation and lactation, and the offspring were subsequently fed vitamin D deficient diets for 3 weeks during the nursery period. Pigs were then assigned to dietary treatment groups with inorganic minerals only or inorganic plus organic (chelated) minerals. Humeral heads were harvested from pigs at 24 weeks of age. Linear elastic modulus and dissipated energy were measured under compression to 15% engineering strain at 1 Hz. Anatomical location within the humeral head affected elastic modulus. Diet significantly affected linear modulus and dissipated energy. The largest modulus and highest energy dissipation was in the inorganic zinc and manganese group; the lowest modulus and the least energy dissipation was in the organic (chelated) zinc and manganese group. Pairwise results between the control group and all vitamin D deficient groups were not statistically significant. Overall, these results suggest that mineral availability during rapid growth subsequent to a vitamin-D deficiency during gestation and lactation had minimal effects on articular cartilage material properties in young growing pigs. Though not statistically significant, some of the numerical differences between mineral sources suggest the potential importance of mineral availability during cartilage formation and warrant further study.